DDFF [1]} uses 2D ConvNets to address the sharpness measurement problem, which is one of the main challenges in depth from focus.
On the other hand, DefocusNet [2]} applies a global pooling layer as a communication tool between several weights-sharing 2D ConvNets.
Another objective of this architecture is to allow focal stacks with arbitrary sizes.
However, some important information across the stack dimension might not be effectively captured due to the limitation of 2D convolution and simple global pooling.
